1 casserole pan 12 by 9" or 9 by 9" dish 2 quart dish
small sauce pan
For the roux
1 ½ tablespons butter
1teaspoonfresh thyme leaves, chopped
½cupparmesan cheese, grated
¾cupcheddar cheese, grated
1 ½ teaspoonkosher salt
For the scalloped potatoes
3pounds yukon potatoes, washed and peeledabout 6-8 potatoes
¼cupparmesan cheese, gratedfor the topping
¼cupcheddar cheese, grated for the topping
butter or oil to grease casserole dish
Preheat oven to 350 degrees Fahrenheit. Lightly grease a 2 quart casserole dish with butter or oil.
Make the roux. Melt the butter in a small saucepan over medium heat. Once it’s sizzling, add the flour and stir with a fork to make a paste, then cook for another minute.
Slowly whisk in the heavy cream, until all of the roux is incorporated, then add the thyme, garlic, salt and pepper, and bring to a light simmer, about 3 minutes.
Once the cream mixture is simmering, stir in ½ cup of parmesan and ¾ cup of cheddar, so it melts into the cream and is smooth, about 30 seconds. Remove pan from heat.
Use a mandoline, sharp knife, or food processor to thinly slice your potatoes to 1/16 inch thickness (about the thickness of a nickel). Transfer all of the slices into a large mixing bowl.
Layer the sliced potatoes in the dish in an even layer, then top with some of the cheese sauce.
Repeat with three more layers of potatoes and cheese sauce.
Sprinkle the remaining ¼ cup of parmesan and ¼ cup of cheddar on top.
Bake in the preheated oven for 65 to 75 minutes uncovered, until potatoes are tender with a nice crusty top.
Let it cool for at least 20 minutes before slicing and serving.
*Nutritional facts provided are only an estimate, accuracy is not guaranteed.
Baking time may vary depending on how thin your potatoes are. If potatoes are on the thicker side, add 15-20 minutes longer. Cooking times may vary, adjust accordingly.
To prevent an overly dark crust, cover the casserole dish with foil after 45 minutes of cooking.
Making a roux with the heavy cream creates a thicker sauce to help keep the potatoes together. From my testing, simply adding the cream and cheese to the dish and baking may prevent the cheese and heavy cream from mixing together, leaving a greasy and watery texture.
To reheat To reheat leftovers, simply rebake in the oven at 350 for 35-45 min. Or use a toaster oven for individual slices.